//remove()移除属性
/* void main(){
  var obj={"name":"wang","age":20};
  obj.remove("name");
  print(obj);          //{age: 20}
} */

//addAll()添加属性
/* void main(){
  var obj={"name":"wang","age":20};
  obj.addAll({"set":"男"});
  print(obj);          //{name: wang, age: 20, set: 男}
} */


//forEach
/* void main(){
  var obj={"name":"wang","age":20};
  obj.forEach((key,value){
    print(key);      //name    age
  });
} */


//map()
 void main(){
  var obj={"name":"wang","age":"20"};
  var m=obj.map((key,value){
    return new MapEntry(key,value+"s");
  });
  print(m);             //{name: wangs, age: 20s}
 }